i'm john donvan for "nightline" in st. louis. >> all ninthings in moderation. >>> coming up next, where do you go to really be alone in this nation of 300 million people? our team tags along with the adventurers looking for the undiscovered corners of america's canyons. i had enough of feeling embarrassed about my skin. [ designer ] enough of just covering up my moderate to severe plaque psoriasis. i decided enough is enough. ♪ [ spa lady ] i started enbrel. it's clinically proven to provide clearer skin. [ rv guy ] enbrel may not work for everyone -- and may not clear you completely, but for many, it gets skin clearer fast, within 2 months, and keeps it clearer up to 9 months. [ male announcer ] because enbrel®, etanercept, suppresses your immune system, it may lower your ability to fight infections. serious, sometimes fatal, events including infections, tuberculosis, lymphoma, other cancers, and nervous system and blood disorders have occurred. before starting enbrel, your doctor should test you for tuberculosis and d